1. Field of the Invention
This invention relates to a safety seat belt system for vehicles. More particularly, it relates to a so-called passive safety seat belt system in which an anchor, a retractor of the like to which the end of the belt is attached, or a through member through which the belt passes is suitably moved in accordance with opening-closing of the door of a vehicle to automatically restrain and liberate the seat occupant.
2. Description of the Prior Art
Various safety seat belt systems of such type have been proposed. They use, however, a motor or the like as the drive means for moving an anchor or the like in response to opening-closing of the door, which leads to various problems regarding the necessity of securing a space for such drive means, ease of fabrication and manufacturing cost which are related to the number of parts, and power consumption and system maintenance.